Are audio cables guilty of sonic differences?

The case made by audiophiles attempting to prove that audio cables routinely sound different from one another wouldn't hold up in court.

Two events this week got me thinking about audio cables again. First, this week's installment of Loudspeakers: Effects of Amplifiers and cables looks into some provable characteristics of cable performance - a topic that's not without its share of controversy, to say the least.

Second, I was called in for jury duty and reminded of how the judicial system works. After spending a good part of a day in voir dire listening to the judge and lawyers explain the process in some detail, I began wondering how the case attempting to prove the general existence of audible differences among audio cables and interconnects - as claimed by many audiophiles - might hold up in court.

Testimonial evidence
One of the things explained to us in the courtroom was that testimony alone was considered sufficient evidence on which to base a case. Other types of evidence - like fingerprints, photos, or DNA evidence etc. - wasn't required in order to prove a case.

So, with hundreds or even thousands of audiophiles claiming to routinely hear differences among loudspeaker and interconnect cables, the prosecutorial case accusing cables of exhibiting audible differences is looking pretty good, right? Well, not so fast.

Burden of proof
In the courtroom, the standard of proof required to prove a case varies (depending on the type of case) and ranges from "the preponderance of the evidence" to "beyond a reasonable doubt." In any case, the evidence presented must be convincing enough to meet that "burden of proof" in order for a case to be successfully prosecuted.

So, how does the testimonial evidence from all those audiophiles claiming to hear differences among cables stack up using these criteria? Unfortunately, not very well.

The susceptibility we all have to self-deception is a well-known phenomenon, and comes as no surprise to those working in the scientific fields. There, the everyday use of the scientific method is aimed at minimizing or eliminating such biases.

Even then they can and do occur, as examples such as the infamous N-ray "discovery" demonstrate. If well-meaning, objective scientists working in their laboratory environments can so easily fall prey to self deception, how convincing can claims based on informal audio cable listening evaluations conducted by laymen audiophiles in their living rooms be?

Nor is the number of such claims - and there are plenty - convincing by itself. The very likely possibility of audiophiles being influenced as part of the group behavior of that community can hardly be ignored.

In court, it's the quality of the testimony that counts. Not the amount of testimony - or number of witnesses.

Motive
The lawyers also explained that a witness's criminal record and/or possible motive to lie shouldn't in and of itself prevent an objective evaluation of their testimony. This actually works in favor of our audiophile accusers, who, having spent hundreds or even thousands of dollars on expensive interconnects, are clearly predisposed to believing that such products make an audible difference.

This isn't, however, a reason - by and of itself - to dismiss their claims out of hand. Nor is the argument - sometimes made by EEs or technical types - that cables "technically shouldn't make a difference." Such arguments are often based on the assumption of theoretically perfect amplifier and/or loudspeaker models, or at least on the use of standard "well-designed" equipment.

Let's face it - there's some pretty weirdly designed stuff out there in audiophile land. That's not necessarily a bad thing - but it can prove more problematical for associated components (like cables and interconnects) than your usual mass-market consumer electronics.

And some esoteric cables themselves are so off-the-wall in their design that it might be more surprising if they didn't sound different (I didn't say "better") under some circumstances compared to conventional cables. (I've seen some so fragile in their construction that they tend to break easily even under normal use. Now that would be an audible difference for sure!)

So dismissing all claims of audible differences among cables out of hand simply because "there shouldn't be any" or because audiophiles "want to hear a difference" may be no more helpful than audiophiles assuming they will sound different because their audiophile peers and professional "golden ear" reviewers claim they do, or because of differences in cable construction or "treatment" or whatever.

Which brings us to ...

Presumption of innocence
In the courtroom, we (the prospective jurors) were asked, if we had to render a verdict at that moment - before any evidence had been presented - what would it be? The answer, of course, would have to be "not guilty" - the presumed status of the defendant unless proven otherwise.

So what's the most reasonable presumption concerning audio cables? Technically, there's little or no reason to believe they should sound different under most normal circumstances, and there's every reason to be skeptical about claims to the contrary. Also, trying to prove a negative - in this case that audio cables don't sound different - is difficult, to say the least.

In court, it isn't up to the defendant to prove him/herself not guilty - it's up to the prosecutor to prove that they are. Likewise, the onus is on those who claim that audible differences commonly exist among cables to prove their case - that cables are "guilty" of sonic differences.

Have they? Not as far as this juror is concerned, which leaves only one possible verdict: Not guilty.

In this particular circumstance we also have to conclude just what _is_ guilt or innocence, so this is not a 'simple' court case.
Clearly there is no such thing as a perfect cable, so our 'innocent' cable must be less than perfect, but how much less then perfect?
Is 'guilty' a nearer to perfect cable that's just a silly price?
Some cheap cables that are notably less then perfect are 'guilty' because they do give noticable degradation. Microphony and poor connectors, for example.
I'd willingly pay for good tightly constructed low-oxygen cables ith conductive plastic interliners and good gold-plated connectors. I might pay for silver plated conductors, though I suspect the benefit is doubtful at best.
Would I pay for cables at hundreds of pounds/dollars a pair? No way. Not guilty, but neither am I that gullible.
Would I pay for cheap thin cables with pressed nickel-plated connectors for an audiophile system? No. And in that case I think a guilty verdict might well be reasonable.